TROPONIN T AND N-TERMINAL PRO-BRAIN NATRIURETIC PEPTIDE CHANGES IN PATIENTS UNDERGOING TRANSURETHRAL RESECTION OF THE PROSTATE

Abstract

We investigated whether transurethral resection of the prostate (TURP) caused subclinical myocardial damage or cardiac dysfunction by measuring troponin T (Trop T) and N-terminal pro-brain natriuretic peptide (pro-BNP). A total of 52 consenting patients took part in this study. All had a detailed medical history including cardiac history taken. On the day of the operation all patients had troponin T, pro-BNP, full blood count and urea, electrolytes and creatinine measured preoperatively. A preoperative and postoperative electrocardiogram was performed. Patients in renal failure were excluded from analysis. During the operations factors such as blood loss, operative time, tissue resected and fluid absorption were monitored. On postoperative day 1 all the previously mentioned tests were repeated. Mean patient age was 71 years (range 52 to 85). Eight patients had a history of associated cardiac problems. Mean preoperative and postoperative hemoglobin were 14.1 gm/dl (range 10.5 to 17) and 13.3 gm/dl (range 9.9 to 16.2), respectively. None of the patients had significant (greater than 1,000 ml) fluid absorption during TURP, which was calculated using ethanol tagged glycine. Mean blood loss measured with a photometer was 129.7 ml (range 0 to 1,800). Mean operative time was 28.4 minutes (range 5 to 50) and mean weight of prostatic tissue resected was 15.2 gm (range 1 to 47). Preoperative Trop T was less than 0.01 mcg/ml in all patients and mean pro-BNP was 39.2 pg/ml (range 0.5 to 866). Postoperative Trop T was less than 0.01 mcg/ml in all but 1 patient who experienced chest pain after TURP and had an increased Trop T (0.28 mcg/ml). Mean postoperative pro-BNP was 54.57 pg/ml (range 1 to 679). A total of 37 patients had an increase in pro-BNP which was still within the reference range for the age group. There were no significant electrocardiogram changes postoperatively. The Trop T changes were not statistically significant (Wilcoxon sign ranked test p = 0.31) although they may be clinically significant. Our study indicates that in patients with no prior cardiac history TURP does not cause myocardial damage indicated by nonincrease of Trop T. There are slight increases in pro-BNP after TURP in some patients although the exact clinical significance is uncertain.